Photocatalytic H2O2 production and removal of Cr (VI) via a novel Lu3NbO7: Yb, Ho/CQDs/AgInS2/In2S3 heterostructure with broad spectral response

The low-usage of solar energy and the sluggish separation efficiency of the photogenerated electrons/holes pairs are the obstacles in the practical application of photocatalysts. The integration of upconversion and Z-scheme heterojunction is expected to break the barriers to achieve the efficient charge separation and broaden near-infrared light absorption . Herein, an effective indirect Z scheme AgInS 2 /In 2 S 3 heterostructure with carbon quantum dots (CQDs, as the electron conduction medium) and Lu 3 NbO 7 :Yb, Ho (as upconversion function) has been successfully synthesized. Consequently, the Lu 3 NbO 7 : Yb, Ho/CQDs/AgInS 2 /In 2 S 3 heterostructure exhibited superior photocatalytic activities for Cr(VI) reduction and H 2 O 2 production, reducing 99.9% of Cr(VI)(20 ppm, 15 min) and 78.5% of Cr(VI) (40 ppm, 30 min) with visible light irradiation as well as 94.0% of Cr(VI) (20 ppm, 39 min) under NIR light irradiation. Simultaneously, the heterostructure could generate 902.9 μM H 2 O 2 for 5 h under visible light irradiation. The intensive photocatalytic properties could primarily be attributed to the boosted light absorption capacity, the improved solar-to-energy conversion by the remarkable upconversion capacity of Lu 3 NbO 7 : Yb, Ho/CQDs and the faster charge transfer through a Z-schematic pathway. This work is anticipated to open a novel “window” for designing the efficient photocatalysts by coupling of Lu 3 NbO 7 : Yb, Ho and CQDs.